Safety switch



Aug, 38, 1925.

F. T. KovAR ET AL SAFETY SWITCH Filed Sept. l2, 1921 2 Sheets-Sheet l ll l l l l um NY .INVENTUM FMNK l? .Km JOJEPH 1'. .7 By 47 Aug. m i925.155mm F. T. KOVAR ET AL SAFETY SWITCH Filed Sept. l2, 1921 2Sheets-Sheet 2 .sk a

IWENIRJ mainz 1: from Patented Aug. 18,Y 1925.

UNITED STATES PATENT oFFlcE.

, FRANK T. KOVAB AND JOSEPH F. JIRXA, 0F CLEVELAND, OHIO.

sAFETY swrrcn.

Application led September 12, 1921. Serial No. 499,877.

-To aZZ'wwm t may comem:

Be it known that FRANK T. KovAR .and

. JOSEPH F. JmxA, who are residents of the Switches, of which thefollowingv is a specif fication.'

This invention relates to safety switches and'to switch operatingmechanism for oo ntrolling electric currents of high amperage, though itwill be evident that it will be useful for circuits of any description.

It is an` object of this invention to provide improved land 'positivelyoperated means for an inclosed type of switch, and especially to renderthe inclosure safe and uniformly efficient even in the hands ofaninexperienced operator.' Another object is to provide a construction ofthis character infwhich pressure mayA beapplied toward and closed with aAthe inclosure either toclos'e or to open the electric circuit, thusmakngthe switch operating means convenient jfor actuation by theoperators `foot. `Another object' is to gprovide a hihged cover sectionfor the inclosure which is so related to the switch` operating elementthat the hinged section cannot he raised or lifted without movingclosing of the circuits when the contact parts are exposed. A furtherobject is the provision of a switch having a novel form ofquickmake-and-break operating mechanism by' which the Yswitch-is bothopened snap, action'y to avoid` a lingering arc. f y i n [Our inventionalso'resides in certain other features of construction and arrangementslot'. partsA whichy will be described in the specificationand set forthin the appended.

claims. It tis, however be expressly to this exact disclosure, tor wemay "depart therefrom in many respects within they ferred form ofembodiment'of the invention:

Fig. l is a top plan view of box and actuating lever.

Figs-2 is a sectional view taken on` the the switch line 2420i Fig.

Fig. 34' is a section taken on the line 3--3 of Fig. 2.'

Fig. et is a face view and Fig. 5 an edge.

view of the rocking lever for actuating the switch bars.

Fig. 6 is a switchV blades, and:

Figs. bracket.

Referrin now to the drawings in detail, the numera 2 designates a baseofinsulating material, such as slate, which.7 is secured to the bottomof an inclosure which is illustrated as a junction box or panel box 1.This box may be made of sheet metal,

though other material may be used. The

cover of the box is made in sections one of which, designated 5 ismovably secured to a fixed kpart 4 by hinges 26. Upon the mainl or fixedpart 4 are mounted vertical sup-J portingbrackets 6 which are shown ashaving leaves 31 cut" out of the body of the bracketsA and then bentback from the same and riveted toL the box cover (see Figs.,` 8w and 9).These brackets also are provided with openings atv the top and bottomends toreceive the pins tl and 23 later tobe deetail .view of-fthe;telescope" 'plunger and roller:

Fig. 7 is a detail of the bar carrying the,

. e5 8 andl 9 are views of the supportir'xg scribed. The .brackets alsohave slots 25 for 8.' The part 9 which, it has been explained, A

extends through the slot 32 in the'cover comp-rises telescoping sections10 which are normally extended to their limit by the forceunderstoodfthat wedo not restrict ourselves.

of an .internally positioned compression spring 11.9 and the cross -baris curved and shapedv to a form convenient for actuation iryrpressureapplied by the foot or hand at elther endiof the bar. The pin 8 may wellbe held against lateral movement by cotter..

pins as shown. The Alower end of the plunger 9 which extends into theinterior of the box is formed into a yoke 15 in which is mounted lforrotation a roller 14 having an enlarged perhhery'interrnediate its facesfor a purpose to e later ex lained.

` The base 2 is provided wlt-h binding posts 22 at the' ends forconnection with con-y ,ductors` to be led into the box through suit-15,v and down movements for opening and closable 'bushings 24. .Nearerthe end of the box having the hinged cover section the base has suitableclips connected by fuses 21,

and the opposite end of the base is provided with spaced switch contacts197 to be connected by the knife blade switch bars 3 adapted to beraised or lowered to open or close 'the circuits.

between the clips and the posts 22 as will be understood. Theblades 3 (2or more) are mounted on a common'nsulatin block 17 :having a centra-lopening `1.8A by w ich its up ing the circuits vis guided by a rigidpost 16 l secured to the base and inserted in said Opern beconnectedwith the block 17 by the beforeable rivets.

1n .the lever is cut out somewhat on either mentioned lu s and links,and less widely ,separated to orm ay groove throughout the remainder oftheir length and `iixedly secured in the parallel relation desired bysuit- One edge of both strips formsi ey of the opening 231toform notches13 with an intervening raised portion so that,

pressure a plied at either notch will tip the correspon ingy endK of'the lever to a 'lower position.

This lever 1 2 is pivoted to the lower or i inner ortions of thebrackets 6 as above describe directly beneath the plunger 9 within thebox` and is* adapted to rock in the Same'plane that the 'plunger 9swings. The roller 14 rides in said roove of the lever and is mounted atsuch a eight that the spring 11 will be under compression even when'theroller rests in the notches. The enlarged central part of the roller 14is guided inv the groove of the lever 12 while the smaller parts ridevon the edges of the lever strips.

For the purpose of locking the switch in the off position, slots 25 areprovided in the outer end of the brackets 6 at the fuse side of thepivot 8. A locking stri 27, preferably secured to the box by ya cham 29,be inserted in the slots immediately may un er the end of the lever 7when raised to lock'the latter in such position.

In operation, assuming that the fuses are 1n proper position, the block17 carryin the blades 3 is mounted on the Apost 16 wit the Suitableconnections [are also made between the contact members andi blades inregister with the contacts 19. The

fuse end of the.. box willv swing the roller 14 into the notch 18nearest the post 16 lowering the blades 3 intothe contacts 19 andclosing the circuits. VSuch relation of the parts 1s marked on the boxas the on position. See the full-line position in Fig. 1. Pressureuponthe opposite end of the lever 7 will obviously open the circuits.

In the closed relation of parts, the lower end of the bar 7 is verycloseto the cover section 5, and forthis reasonthe latter can-` not beraised without first moving the switch lever and opening the circuits;and if the hinged section is forcibly lifted, it will automaticallyshift the switch whether this function is` intended or not. Thistherefore pro-` vides a safety element whereby the operator cannotincurthe danger of exposing the fuse end of the box while the circuitsare closed.

It will be evident that the disclosed operating mechanism can well beused for operating many kinds of switch elements other than thosedisclosed herein, and applicants by no means conne this invention to theparticular make-and-break means here shown. It will be obvious that alaminated brush of metal leaves may be substituted for the blades 3, inwhich case the ends would contact with 'a suitable conducting plateinstead of the contacts 19. It will also be evident that the describedactuating means for ythe switch may be "advantageously used foroperating more than two pairs of bars 3 or for controlling more than onecircuit. In fact a number of such switch blades may be mounted on thesame block 17.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent, is: y

1. HIn a safety switch, *an inclosing means for -spaced contact pointsand movable means for bridging the gap between the said points, incombination wlth a support secured-.to a fixed cover section of saidinclosure and extending above and below said cover, a rocking leverivoted to the outer end of said support so t at pressure applied toeither end of said lever will rock the same, there being slots in saidouter end immediatel beneath one end of said lever, a locking ar adaptedto be inserted in said slots to prevent the actuation of said lever, andmeans including a part pivoted to the inner portion of said support,connected with said lever for actuating the said bridging means.

2. In a safety switch, a support for spaced contact members, aninclosing means for said members and movable means for bridging the apbetween said -members Yto close a circuit, in combination with a supportlil - hinged directly beneath one end of the rock- .ing lever, so thatthe closure 'of the switch ",is prevented when the box is open, andtheis moving. of the coversection to open the box will automatically openthe switch. 3. A safety switch comprising a movable insulating barcarryingelectrical conducting members*4 for bridging the gap betweenspacediccntact elements to close a circuit, an inclosurc for said barand conducting members, having fixed andv movable cover sectiens, incombination with apair of support brackets spaced apart in parallelismand having leaves cu't out thereof and bent back therefrom and rivetedto said fixed cover section to, mount said brackets to extend outsidethe box and within the same, ,a pivoted operating lever Jmounted on theouter extension so that the lever will rock f the application ofpressure to either end thereof', the movable cover section being lhingeddirectly beneath bue end of the rock# ing lever so that opening the saidhinged sectionwill rock the-lever if said end of the latter is down,means for locking the lever dit' when said end is raised, and meansmounted on the inner extensions of said'brackets for actuating the saidbar by rocking the lever,

yl. A. safety switch comprising, an insulating support for spacedcontact points, means for bridging the gap between said points and aninclosingmeans forsaid support and 5. A safety switch comprising aswitch box having a support for fuse terminals and both power and loadconductors, and a sectional cover, a lswitch arranged to connect anddisconnect saidfuse terminals with said conductors, a lever )pivoted toa fixed section of said cover and having connections at one end withopening and closing elements of said switch and notches at the other endthereof situated on either side of the pivot for said lever, aspring-pressed plunger pivoted on the outer face of said fixed coversection and having a roller on one end thereof for engaging the saidnotches selectively, and man-nahoperating' means on the` outer face ofsaidcove sec-v #tion for actuating the said `plunger to open or to closethe circuit, said means belng operable for either purpose by pressureap.- plied ina directiontoward the said support.

6. A safety switch comprising in combination, afix'edp'ost for guidingthe vertical 4movement of electrical conducting members its relatedstructure, includinga cover hav-.

ing fixed )and .movablef sections, a lever; "plvotallyl mounted on `saidfixed cover' s'ecj;l tion but within thefinclosure, and havlngff'connections at one v,endfvv'ith saidv bridging means for yactuating thelatter and notches l adjacentits other,A end on opposite sides ofv itspivot, in; rcombination with a plvotedA operating lever mounted on theouter facep ofsaid fixed cover section, so that it will rock by theapplicatien-of-` pressureto either end thereof, actuating means for saidnotched lever, .connected with said pressure-actu ated lever andincluding a swinging plunger element carrying a roller for engaging saidnotched lever and seating in said notches, selectively, said movablecover section being hinged directly beneath one end of the rockinglever, so that opening 4said hinged section will rock the lever, if theadjacent end of' the lever is down and thereby opent-he switch.; i Y

for Vbridging the gap between spaced contact elements when sald membersare in the down position, a fixed vertical supporting member positionedabove 4said, elements, a swinging lever pivoted on the lower end of saidsupporting member and having .connections with said members at `one endand a pair of connected notches, at the other "end, the pivotal point`of the'lever being between the notches so that pressure applied ateither notch will lowerthe corresponding end of the lever to raise orlower the said conductl ing members and thereby open or bridge'th'e 5said gap, and actuating means including a plunger pivoted on the upperend bf said supporting member manually operable byl pressure thereon atspaced portions thereof for applying pressure to the respective notchesselectively. y

7, In combination, arSw-itch base of insulating/material, an elongatedsupport lixed relative to and at an angle to the plane of ysaid base,spaced contacts on said base, conf susv ducting elements'mounted formovement to and from said contacts, a lever pivoted to the lower end 'ofsaid support and having connectionswith said conducting elements at oneend 1nd notches adjacent the other end on opposite sides of the fulcrum,a plunger l element having 'a cross bar lixedly secured to one of itsends `and a roller rotatably mounted on the other end, the said plungerelementbeing mounted on the upper end of saidsupport forswinging-movement above said p ivoted lever so that-"said roller mayengage one of said notches in said lever, and follow the contour of theedgeof the lever as it passes from one notch to the other during theswinging movement of the plunl ger element. u

8.l In a safetyl switch, an inclosing means for spaced contact pointsand movable means for bridging /the gailbetween the said points,l

low said cover'and secured'to the said fixed section, a rocking leverivoted to `the outer end of said support so t at pressure a ilied towardthe cover at either end offsai ever will rock the same, means mounted onthe lower extension of said sup ort' for actuating said bridging meansan having oper`aty ing connections with said rockin lever, the A saidhinged cover section beingl irectly beneath one end of the said lever sothat opening said hinged section will rock the lever, if the adjacentend of the lever is down and thereby openthe switch.' n f,

In testimony whereof we. `hereunto aix our signatures'.

FRANK -T. KovAn. JOSEPH r. JIRKA,

